(a) Technical Field
The present invention relates to a dye-sensitized solar cell. More particularly, it relates to a method for preparing a polymer thin film electrolyte, which is used to improve to long-term durability of a solar cell, and a dye-sensitized solar cell comprising the electrolyte prepared by the method.
(b) Background Art
Recently, as global warming becomes more of an issue, technology for using environmentally-friendly energy has attracted much attention. An attractive field, in particular, is solar cells which use new and renewable energy. Examples of such solar cells include silicon-based solar cells, thin film solar cells using inorganic substances such as copper indium gallium selenide (Cu(InGa)Se2, CIGS), dye-sensitized solar cells, organic solar cells, organic-inorganic hybrid solar cells, etc. Among them, the dye-sensitized solar cells, which are inexpensive and have a commercial grade energy efficiency, have attracted attention in the field of portable electronics as well as in the field of building integrated photovoltaics (BIPV).
Unlike other solar cells, the dye-sensitized solar cell is provided with a solar cell system which absorbs visible light and produces electricity by a photoelectric conversion mechanism. Typically, the dye-sensitized solar cell uses a liquid electrolyte or a gel polymer electrolyte. This liquid electrolyte or gel polymer electrolyte may leak due to damage of a solar cell substrate, which may reduce its merchantability/cost efficiency and may further damage the health of consumers due to the toxicity of the electrolyte.
For these reasons, the development of solid electrolytes has recently been actively to pursued. Typically, the solid electrolyte completely dries a solvent on the surface of a photoelectrode (TiO2) of the dye-sensitized solar cell. In this case, the current density is very low, and thus the efficiency of the solar cell cannot be expected. A technique of controlling a porous structure by electrospinning has been known, but it requires high initial investment, and the types of available polymer materials are limited.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.